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Free space optics (fso) seminar report full

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Free Space Optics
[Department of Computer Science and Engineering] Page 1
A
SEMINAR REPORT
ON
“Screenless Display Technolo...
Free Space Optics
[Department of Computer Science and Engineering] Page 2
Certificate
This is to Certified that the semina...
Free Space Optics
[Department of Computer Science and Engineering] Page 3
ACKNOWLEDGEMENT
I would like to take this opport...
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Free Space Optics (FSO) communications, also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. Free Space Optics (FSO) works on the same basic principle as Infrared television remote controls, wireless keyboards

Free Space Optics (FSO) communications, also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. Free Space Optics (FSO) works on the same basic principle as Infrared television remote controls, wireless keyboards

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Free space optics (fso) seminar report full

  1. 1. Free Space Optics [Department of Computer Science and Engineering] Page 1 A SEMINAR REPORT ON “Screenless Display Technology” As a Partial Fulfillment For The Degree of Bachelor of Engineering in Computer Science & Engineering 3rd Year (5th Semester) YEAR: - 2014 Guided By: Prepared By: Prof. Chandani A Naik Dilip j. Prajapati Faculty of Engineering Technology & Research, Isroli-Bardoli Department of Computer Science & Engineering
  2. 2. Free Space Optics [Department of Computer Science and Engineering] Page 2 Certificate This is to Certified that the seminar entitled FREE SPACE OPTICS carried out by Mr. Dilip J. Prajapati PEN 130843131016 in partial fulfillments for the award of Bachelor of Engineering in Computer Science & Engineering of Faculty of Engineering Technology & Research, Isroli-Bardoli during the Academic year 2014-2015. It is certified that all corrections/suggestions indicated for Internal Assessment have been incorporated in the Report. The seminar report has been approved as it satisfies the academic requirements in respect of seminar work prescribed for the said Degree. Seminar Guide H. O. D. Prof. C A Naik Prof. B R Bhatt
  3. 3. Free Space Optics [Department of Computer Science and Engineering] Page 3 ACKNOWLEDGEMENT I would like to take this opportunity to best my acknowledgements to all the persons who have directly or indirectly been involved with me in making my seminar feasible and to run it up into a successful piece of work. A report as all encompassing as this is never the work of one or two people laboring in quiet solitude. It is the product of many hands, and countless hours from many people. My thanks go to all those who helped, whether through their comments, feedback, edits or suggestions. I express a deep sense of gratitude to the Head of the Computer Science and Engineering Department, Prof. Bhavini R Bhatt and guide Prof. Chandani A Naik who has helped me throughout my seminar. How can I forget my college? Without whom I can’t do anything. I would like to thank my management for their invaluable support. Their patience, understanding and love gave us strength and will power to work through the long tedious hours in studying the subject and preparing the report. Last but not the least, I would also like to thank my friends and classmates who co-operated during the preparation of my seminar report and without them this report has not been possible. Their ideas helped me a lot to improve my project report. Dilip J. Prajapati 130843131016
  4. 4. Free Space Optics [Department of Computer Science and Engineering] Page 4 ABSTRACT Free Space Optics (FSO) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the air to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. It is a secure, cost-effective alternative to other wireless connectivity options. This form of delivering communication has a lot of compelling advantages. Data rates comparable to fiber transmission can be carried with very low error rates, while the extremely narrow laser beam widths ensure that it is possible to co- locate multiple transceivers without risk of mutual interference in a given location. FSO has roles to play as primary access medium and backup technology. It could also be the solution for high speed residential access. Though this technology sprang into being, its applications are wide and many. It indeed is the technology of the future.
  5. 5. Free Space Optics [Department of Computer Science and Engineering] Page 5 INDEX Sr. No.TITLE Page No. ABSTRACT 1 INTRODUCTION1 1.1 DEFINIATION1 2 HISTROY2 3 HOW FREE SPACE OPTICS (FSO)WORKS 3 3.1 OPTICAL COMMUNICATION 5 3.2FSO:Wireless, at the Speed of Light 5 4 FSO ARCHITECTURES 6 4.1 POINT TO POINT 6 4.2 MESH ARCHITECTURE 6 4.3 POINT TO MULTIPOINT ARCHITECTURE 7 5 WHY FSO?8 6 APPLICATION OF FSO9 7 ADVANTAGES OF FSO11 8FREE SPACE OPTICS (FSO) SECURITY12 9 FSO CHALLENGES 13 10 CONCULSION16 REFRENCES 18
  6. 6. Free Space Optics [Department of Computer Science and Engineering] Page 6 LIST OF FIGURES FIG. NO. TITLE PAGE NO. 3 (A) FSO WORKING 3 3 (B) FSO SUBSYSTEM WORK 4 3 (C) THE COMPONENTS OF A SENSOR NODE 5 4 (A) POINT TO POINT ARCHITECTURE 6 4 (B) MESH ARCHITECTURE 6 4 (C) POINT TO MULTIPOINT ARCHITECTURE 7 9 (A) FOG 14 9 (B) SCINTILLATION 15
  7. 7. Free Space Optics [Department of Computer Science and Engineering] Page 7 Chapter 1 Introduction Free Space Optics (FSO) communications, also called Free Space Photonics (FSP) or Optical Wireless, refers to the transmission of modulated visible or infrared (IR) beams through the atmosphere to obtain optical communications. Like fiber, Free Space Optics (FSO) uses lasers to transmit data, but instead of enclosing the data stream in a glass fiber, it is transmitted through the air. Free Space Optics (FSO) works on the same basic principle as Infrared television remote controls, wireless keyboards or wireless Palm devices. 1.1 Definition Free space optics or FSO, free space photonics or optical wireless, refers to the transmission of modulated visible or infrared beams through the atmosphere to obtain optical communication. FSO systems can function over distances of several kilometers. FSO is a line-of-sight technology, which enables optical transmission up to 2.5 Gbps of data, voice and video communications, allowing optical connectivity without deploying fiber optic cable or securing spectrum licenses. Free space optics require light, which can be focused by using either light emitting diodes (LED) or LASERS(light amplification by stimulated emission of radiation). The use of lasers is a simple concept similar to optical transmissions using fiber-optic cables, the only difference being the medium. As long as there is a clear line of sight between the source and the destination and enough transmitter power, communication is possible virtually at the speed of light. Because light travels through air faster than it does through glass, so it is fair to classify FSO as optical communications at the speed of light.
  8. 8. Free Space Optics [Department of Computer Science and Engineering] Page 8 Chapter 2 History The engineering maturity of Free Space Optics (FSO) is often underestimated, due to a misunderstanding of how long Free Space Optics (FSO) systems have been under development. Historically, Free Space Optics (FSO) or optical wireless communications was first demonstrated by Alexander Graham Bell in the late nineteenth century (prior to his demonstration of the telephone!). Bell’s Free Space Optics (FSO) experiment converted voice sounds into telephone signals and transmitted them between receivers through free air space along a beam of light for a distance of some 600 feet. Calling his experimental device the “photophone,” Bell considered this optical technology – and not the telephone – his preeminent invention because it did not require wires for transmission. Although Bell’s photophone never became a commercial reality, it demonstrated the basic principle of optical communications. Essentially all of the engineering of today’s Free Space Optics (FSO) or free space optical communications systems was done over the past 40 years or so, mostly for defense applications. By addressing the principal engineering challenges of Free Space Optics (FSO), this aerospace/defense activity established a strong foundation upon which today’s commercial laser-based Free Space Optics (FSO) systems are based.
  9. 9. Free Space Optics [Department of Computer Science and Engineering] Page 9 Chapter 3 How Free Space Optics (FSO) Works Optical systems work in the infrared or near infrared region of light and the easiest way to visualize how the work is imagine, two points interconnected with fiber optic cable and then remove the cable. The infrared carrier used for transmitting the signal is generated either by a high power LED or a laser diode. Two parallel beams are used, one for transmission and one for reception, taking a standard data, voice or video signal, converting it to a digital format and transmitting it through free space. Today’s modern laser system provide network connectivity at speed of 622 Mega bits/sec and beyond with total reliability. The beams are kept very narrow to ensure that it does not interfere with other FSO beams. The receive detectors are either PIN diodes or avalanche photodiodes. Fig. 3 (A):- FSO Working The FSO transmits invisible eye safe light beams from transmitter to the receiver using low power infrared lasers in the tera hertz spectrum. FSO can function over kilometers.
  10. 10. Free Space Optics [Department of Computer Science and Engineering] Page 10 Wavelength: Currently available FSO hardware is of two types based on the operating wavelength – 800 nm(nanometer) and 1550 nm. 1550 FSO systems are selected because of more eye safety, reduced solar background radiation and compatibility with existing technology infrastructure. Subsystem: Fig. 3(B):- FSO Subsystem work In the transmitting section, the data is given to the modulator for modulating signal and the driver is for activating the laser. In the receiver section the optical signal is detected and it is converted to electrical signal, preamplifier is used to amplify the signal and then given to demodulator for getting original signal. Tracking system which determines the path of the beam and there is special detector (CCD, CMOS) for detecting the signal and given to pre amplifier. The servo system is used for controlling system, the signal coming from the path to the processor and compares with the environmental condition, if there is any change in the signal then the servo system is used to correct the signal. Modulator Driver Laser TransmitopticData in De-Modulator preamplifier detector Receive opticData out preamplifier Special detector Trackingoptic Processor Servo systems Environmental condition
  11. 11. Free Space Optics [Department of Computer Science and Engineering] Page 11 3.1Optical Communication Optical communication is any form of telecommunication that uses light as the transmission medium.An optical communication system consists of a transmitter, which encodes amessageinto an optical signal, a channel, which carries the signal to itsdestination, and a receiver, which reproduces the message from the received optical signal. Fig. 3.1(C): - Optical communication 3.2 FSO: Wireless, At the Speed of Light Unlike radio and microwave systems, Free Space Optics (FSO) is an optical technology and no spectrum licensing or frequency coordination with other users is required, interference from or to other systems or equipment is not a concern, and the point-to-point laser signal is extremely difficult to intercept, and therefore secure. Data rates comparable to optical fiber transmission can be carried by Free Space Optics (FSO) systems with very low error rates, while the extremely narrow laser beam widths ensure that there is almost no practical limit to the number of separate Free Space Optics (FSO) links that can be installed in a given location.
  12. 12. Free Space Optics [Department of Computer Science and Engineering] Page 12 Chapter 4 FSO Architectures 4.1 Point-To-Point Architecture Point-to-point architecture is a dedicated connection that offers higher bandwidth but is less scalable .In a point-to-point configuration, FSO can support speeds between 155Mbits/sec and 10Gbits/sec at a distance of 2 kilometers (km) to 4km. “Access” claims it can deliver 10Gbits/ sec. “Terabeam” can provide up to 2Gbits/sec now, while “AirFiber” and “Lightpointe” have promised Gigabit Ethernet capabilities sometime in 2001.. Fig 4 (A):- Point to Point Architecture 4.2 Mesh Architecture Mesh architectures may offer redundancy and higher reliability with easy node addition but restrict distances more than the other options. Fig. 4 (B):- Mesh Architecture
  13. 13. Free Space Optics [Department of Computer Science and Engineering] Page 13 A meshed configuration can support 622Mbits/sec at a distance of 200 meters (m) to 450m. TeraBeam claims to have successfully tested 160Gbit/sec speeds in its lab, but such speeds in the real world are surely a year or two off. 4.3 Point-.To-Multipoint Architecture Point-to-multipoint architecture offers cheaper connections and facilitates node addition but at the expense of lower bandwidth than the point-to-point option. Fig 4 (c):- Point to multipoint Architecture In a point-to-multipoint arrangement, FSO can support the same speeds as the point-to-point arrangement -155Mbits/sec to 10Gbits/sec-at 1km to 2km.
  14. 14. Free Space Optics [Department of Computer Science and Engineering] Page 14 Chapter 5 Why FSO? The increasing demand for high bandwidth in metro networks is relentless, and service providers' pursuit of a range of applications, including metro network extension, enterprise LAN-to-LAN connectivity, wireless backhaul and LMDS supplement has created an imbalance. This imbalance is often referred to as the "last mile bottleneck." Service providers are faced with the need to turn up services quickly and cost-effectively at a time when capital expenditures are constrained. But the last mile bottleneck is only part of a larger problem. Similar issues exist in other parts of the metro networks. "Connectivity bottleneck" better addresses the core dilemma. As any network planner will tell you, the connectivity bottleneck is everywhere in metro networks. From a technology standpoint, there are several options to address this "connectivity bottleneck," but most don't make economic sense. The first, most obvious choice is fiber-optic cable. Without a doubt, fiber is the most reliable means of providing optical communications. But the digging, delays and associated costs to lay fiber often make it economically prohibitive. Moreover, once fiber is deployed, it becomes a "sunk" cost and cannot be re-deployed if a customer relocates or switches to a competing service provider, making it extremely difficult to recover the investment in a reasonable timeframe. Another option is radio frequency (RF) technology. RF is a mature technology that offers longer ranges distances than FSO, but RF-based networks require immense capital investments to acquire spectrum license. Yet, RF technologies cannot scale to optical capacities of 2.5 gigabits. The current RF bandwidth ceiling is 622 megabits. When compared to FSO, RF does not make economic sense for service providers looking to extend optical networks.
  15. 15. Free Space Optics [Department of Computer Science and Engineering] Page 15 The third alternative is wire- and copper-based technologies, (i.e. cable modem, T1s or DSL). Although copper infrastructure is available almost everywhere and the percentage of buildings connected to copper is much higher than fiber, it is still not a viable alternative for solving the connectivity bottleneck. The biggest hurdle is bandwidth scalability. Copper technologies may ease some short-term pain, but the bandwidth limitations of 2 megabits to 3 megabits make them a marginal solution, even on a good day. The fourth-and often most viable-alternative is FSO. The technology is an optimal solution, given its optical base, bandwidth scalability, speed of deployment (hours versus weeks or months), re-deployment and portability, and cost-effectiveness (on average, one-fifth the cost of installing fiber-optic cable). Only 5 percent of the buildings in the United States are connected to fiber-optic infrastructure (backbone), yet 75 percent are within one mile of fiber. As bandwidth demands increase and businesses turn to high-speed LANs, it becomes more frustrating to be connected to the outside world through lower-speed connections such as DSL, cable modems or T1s. Most of the recent trenching to lay fiber has been to improve the metro core (backbone), while the metro access and edge have completely been ignored. Studies show that disconnects occurs in the metro network core, primarily due to cost constraints and the deployment of such non-scalable, non-optical technologies such as LMDS. Metro optical networks have not yet delivered on their promise. High capacity at affordable prices still eludes the ultimate end-user.
  16. 16. Free Space Optics [Department of Computer Science and Engineering] Page 16 Chapter 6 Applications of FSO Optical communication systems are becoming more and more popular as the interest and requirement in high capacity and long distance space communications grow. FSO overcomes the last mile access bottleneck by sending high bit rate signals through the air using laser transmission. Applications of FSO system are many and varied but a few can be listed. 1. Metro Area Network (MAN): FSO network can close the gap between the last mile customers, there by providing access to new customers to high speed MAN’s resulting to Metro Network extension. 2. Last Mile Access: End users can be connected to high speed links using FSO. It can also be used to bypass local loop systems to provide business with high speed connections. 3. Enterprise connectivity: As FSO links can be installed with ease, they provide a natural method of interconnecting LAN segments that are housed in buildings separated by public streets or other right-of-way property. 4. Fiber backup: FSO can also be deployed in redundant links to backup fiber in place of a second fiber link. 5. Backhaul: FSO can be used to carry cellular telephone traffic from antenna towers back to facilities wired into the public switched telephone network. 6. Service acceleration: Instant services to the customers before fiber being laid.
  17. 17. Free Space Optics [Department of Computer Science and Engineering] Page 17 Chapter 7 Advantages of FSO Free space optical (FSO) systems offer a flexible networking solution that delivers on the promise of broadband. Only free space optics or Free Space Optics (FSO) provides the essential combination of qualities required to bring the traffic to the optical fiber backbone – virtually unlimited bandwidth, low cost, ease and speed of deployment. Freedom from licensing and regulation translates into ease, speed and low cost of deployment. Since Free Space Optics (FSO) optical wireless transceivers can transmit and receive through windows, it is possible to mount Free Space Optics (FSO) systems inside buildings, reducing the need to compete for roof space, simplifying wiring and cabling, and permitting the equipment to operate in a very favorable environment. The only essential for Free Space Optics (FSO) is line of sight between the two ends of the link.
  18. 18. Free Space Optics [Department of Computer Science and Engineering] Page 18 Chapter 8 Free Space Optics (FSO) Security Security is an important element of data transmission, irrespective of the network topology. It is especially important for military and corporate applications. Building a network on the SONA beam platform is one of the best ways to ensure that data transmission between any two points is completely secure. Its focused transmission beam foils jammers and eavesdroppers and enhances security. Moreover, fSONA systems can use any signal-scrambling technology that optical fiber can use. The common perception of wireless is that it offers less security than wire line connections. In fact, Free Space Optics (FSO) is far more secure than RF or other wireless-based transmission technologies for several reasons:  Free Space Optics (FSO) laser beams cannot be detected with spectrum analyzers or RF meters.  Free Space Optics (FSO) laser transmissions are optical and travel along a line of sight path that cannot be intercepted easily. It requires a matching Free Space Optics (FSO) transceiver carefully aligned to complete the transmission. Interception is very difficult and extremely unlikely.  The laser beams generated by Free Space Optics (FSO) systems are narrow and invisible, making them harder to find and even harder to intercept and crack.  Data can be transmitted over an encrypted connection adding to the degree of security available in Free Space Optics (FSO) network transmissions.
  19. 19. Free Space Optics [Department of Computer Science and Engineering] Page 19 Chapter 9 FSO Challenges The advantages of free space optical wireless or Free Space Optics (FSO) do not come without some cost. When light is transmitted through optical fiber, transmission integrity is quite predictable – barring unforeseen (unexpected) events such as backhoes or animal interference. When light is transmitted through the air, as with Free Space Optics (FSO) optical wireless systems, it must contend with a complex and not always quantifiable subject - the atmosphere. 1. FOG Fig. 9 (A):- Fog Fog substantially attenuates visible radiation, and it has a similar affect on the near- infrared wavelengths that are employed in FSO systems. Rain and snow have little effect on FSO. Fog being microns in diameter, it hinder the passage of light by absorption, scattering and reflection. Dealing with fog – which is known as Mie – scattering, is largely a matter of boosting the transmitted power. Fog can be countered by a network design with short FSO link distances. FSO installation in foggy cities like San Francisco has successfully achieved carrier-class reliability.
  20. 20. Free Space Optics [Department of Computer Science and Engineering] Page 20 2. Physical Obstructions Flying birds can temporarily block a single beam, but this tends to cause only short interruptions and transmissions are easily and automatically re-assumed. Multi-beam systems are used for better performance. 3. Scintillation Fig. 9(A):-Scintillation Scintillation refers the variations in light intensity caused by atmospheric turbulence. Such turbulence may be caused by wind and temperature gradients which results in air pockets of varying diversity act as prisms or lenses with time varying properties. This scintillation affects on FSO can be tackled by multi beam approach exploiting multiple regions of space- this approach is called spatial diversity. 4. Solar Interference This can be combated in two ways:  The first is a long pass optical filter window used to block all wavelengths below 850nm(nenometre) from entering the system.  The second is an optical narrow band filter proceeding the receive detector used to filter all but the wavelength actually used for intersystem communications. 5. Scattering
  21. 21. Free Space Optics [Department of Computer Science and Engineering] Page 21 Scattering is caused when the wavelength collides with the scatterer. The physical size of the scatterer determines the type of scattering.  When the scatterer is smaller than the wavelength-Rayleigh scattering.  When the scatterer is of comparable size to the wavelength -Mie scattering.  When the scatterer is much larger than the wavelength-Non-selective scattering In scattering there is no loss of energy, only a directional re-distribution of energy which may cause reduction in beam intensity for longer distance. 6. Absorption Absorption occurs when suspended water molecules in the terrestrial atmosphere extinguish photons. This causes a decrease in the power density of the FSO beam and directly affects the availability of a system. Absorption occurs more readily at some wavelengths than others. However, the use of appropriate power, based on atmospheric conditions, and use of spatial diversity helps to maintain the required level of network availability. 7. Building Sway / Seismic Activity One of the most common difficulties that arises when deploying FSO links on tall buildings or towers is sway due to wind or seismic activity Both storms and earthquakes can cause buildings to move enough to affect beam aiming. The problem can be dealt with in two complementary ways: through beam divergence and active tracking  With beam divergence, the transmitted beam spread, forming optical cones which can take many perturbations.  Active tracking is based on movable mirrors that control the direction in which beams are launched.
  22. 22. Free Space Optics [Department of Computer Science and Engineering] Page 22 Chapter 10 Conclusion FSO enables optical transmission of voice video and data through air at very high rates. It has key roles to play as primary access medium and backup technology. Driven by the need for high speed local loop connectivity and the cost and the difficulties of deploying fiber, the interest in FSO has certainly picked up dramatically among service providers world wide. Instead of fiber coaxial systems, fiber laser systems may turn out to be the best way to deliver high data rates to your home. FSO continues to accelerate the vision of all optical networks cost effectively, reliably and quickly with freedom and flexibility of deployment.
  23. 23. Free Space Optics [Department of Computer Science and Engineering] Page 23 Reference 1. Vikrant kaulgnd, “Free space optics Bridges the last mile’’ ,Electronics for u , June 2003 pp . 38-40 . 2. Andy Emmerson , “ Fibreless Optics ’’ , Everyday practical electronics , April 2003 pp . 248 . Websites: 3. www.fsona.com 4. www.freespaceoptics.com 5. www.freespaceoptic.com 6. www.fsocentral.com 7. www.lightpointe.com 8. www.spie.org 9. www.osa.org

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